Add counter-write and counter-read commands.

Add counter-write and counter-read commands.

BUG=639709
Committed: https://github.com/luci/luci-go/commit/6f90e9fa9ff7d57f4fafffbbf7f6916c57e7b673

[dsansome, 2016-09-06 10:20:09]

dsansome@chromium.org changed reviewers:
+ vadimsh@chromium.org

[dsansome, 2016-09-06 10:20:09]

$ ./cipd counter-read --service-url
https://chrome-infra-packages-dev.appspot.com --version latest
infra/tools/cipd/linux-386 test.counter foo.bar
Package:       infra/tools/cipd/linux-386
Instance ID:   a1af4e9ebdee5ca4aa6ae872292f1d1afb9d249c

Counter:       test.counter
Value:         12
Created at:    2016-09-06 17:18:54.38431 +1000 AEST
Last updated:  2016-09-06 19:49:41.89339 +1000 AEST

Counter:       foo.bar
Value:         0

[Vadim Sh., 2016-09-06 21:32:27]

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.go
File cipd/client/cmd/cipd/main.go (right):

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1712: return 1
please use c.done(...) in all branches. It dumps results to json file specified
by -json-output.

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1775: func readCounters(ctx context.Context, pkg,
version string, counters []string, opts *ClientOptions) error {
the result of this call should be piped to -json-output too (by passing
JSON-serializable struct to c.done on line 1772 instead of first nil there).

I propose something like

type CounterReadResult struct {
  cipd.Counter

  Error string `json:"error"`
}

and also add `json:...` tags to cipd.Counter (and switch time.Time to UnixTime
there because parsing default Go time from python is PITA).

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1823: fmt.Printf("Failed to read counter: %s\n",
err)
return non-nil overall error if at least one counter read failed

[dsansome, 2016-09-07 01:27:55]

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.go
File cipd/client/cmd/cipd/main.go (right):

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1712: return 1
On 2016/09/06 21:32:27, Vadim Sh. wrote:
> please use c.done(...) in all branches. It dumps results to json file
specified
> by -json-output.

Done.

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1775: func readCounters(ctx context.Context, pkg,
version string, counters []string, opts *ClientOptions) error {
On 2016/09/06 21:32:27, Vadim Sh. wrote:
> the result of this call should be piped to -json-output too (by passing
> JSON-serializable struct to c.done on line 1772 instead of first nil there).
> 
> I propose something like
> 
> type CounterReadResult struct {
>   cipd.Counter
> 
>   Error string `json:"error"`
> }
> 
> and also add `json:...` tags to cipd.Counter (and switch time.Time to UnixTime
> there because parsing default Go time from python is PITA).

Done.

https://codereview.chromium.org/2317633002/diff/1/cipd/client/cmd/cipd/main.g...
cipd/client/cmd/cipd/main.go:1823: fmt.Printf("Failed to read counter: %s\n",
err)
On 2016/09/06 21:32:27, Vadim Sh. wrote:
> return non-nil overall error if at least one counter read failed

Done.

[Vadim Sh., 2016-09-07 02:43:26]

lgtm with nits

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cipd/client.go
File cipd/client/cipd/client.go (right):

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cipd/client...
cipd/client/cipd/client.go:217: CreatedTS UnixTime `json:"created_ts"`
maybe `json:"created_ts,omitempty"` and then IsZero check is unnecessary?

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cmd/cipd/ma...
File cipd/client/cmd/cipd/main.go (right):

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cmd/cipd/ma...
cipd/client/cmd/cipd/main.go:1776: Error error `json:"error"`
`json:"error,omitempty"`

[dsansome, 2016-09-07 03:30:54]

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cipd/client.go
File cipd/client/cipd/client.go (right):

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cipd/client...
cipd/client/cipd/client.go:217: CreatedTS UnixTime `json:"created_ts"`
On 2016/09/07 02:43:25, Vadim Sh. wrote:
> maybe `json:"created_ts,omitempty"` and then IsZero check is unnecessary?

Doesn't work :(
The docs say: "The empty values are false, 0, any nil pointer or interface
value, and any array, slice, map, or string of length zero."
time.Time{} is not any of these.

[dsansome, 2016-09-07 03:31:05]

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cmd/cipd/ma...
File cipd/client/cmd/cipd/main.go (right):

https://codereview.chromium.org/2317633002/diff/20001/cipd/client/cmd/cipd/ma...
cipd/client/cmd/cipd/main.go:1776: Error error `json:"error"`
On 2016/09/07 02:43:26, Vadim Sh. wrote:
> `json:"error,omitempty"`

Done.

[dsansome, 2016-09-07 03:31:12]

The CQ bit was checked by dsansome@chromium.org

[dsansome, 2016-09-07 03:31:12]

The patchset sent to the CQ was uploaded after l-g-t-m from vadimsh@chromium.org
Link to the patchset: https://codereview.chromium.org/2317633002/#ps40001
(title: "CL comments")

[commit-bot: I haz the power, 2016-09-07 03:31:20]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-07 03:39:47]

Description was changed from

==========
Add counter-write and counter-read commands.

BUG=639709
==========

to

==========
Add counter-write and counter-read commands.

BUG=639709

Committed:
https://github.com/luci/luci-go/commit/6f90e9fa9ff7d57f4fafffbbf7f6916c57e7b673
==========

[commit-bot: I haz the power, 2016-09-07 03:39:48]

Committed patchset #3 (id:40001) as
https://github.com/luci/luci-go/commit/6f90e9fa9ff7d57f4fafffbbf7f6916c57e7b673